The present invention relates to a magnetic tape loading method and apparatus therefor. More particularly, the invention relates to a magnetic tape loading method and apparatus for initially loading a magnetic tape on a flangeless-type tape winding body in a cassette such as an audio tape cassette, a digital audio cassette or the like.
The known processes for manufacturing magnetic tapes, such as audio cassette tapes, video cassette tapes and the like include a process for winding a magnetic tape of a predetermined width on a small-diameter flangeless type tape winding body such as a reel, a hub or the like, from a roll of "raw" magnetic tape, as an intermediate manufacturing process.
In the case where a magnetic tape is wound on a tape winding body using such a process, various tape winding characteristics such as vibration in the direction of tape thickness, vibration in the direction of tape width, and the like change according to the physical properties of the raw magnetic tape, the physical properties of the tape winding body, and the physical properties of the magnetic tape itself. As a result, a problem arises in regard to the winding appearance (winding condition) of the magnetic tape wound on the tape winding body. In other words, winding difficulties arise so that the edges of the tape are uneven. Particularly, as the tape running speed during winding is increased, the tape edges become more uneven.
Of course, a magnetic tape in which the tape edges are uneven has a poor external appearance when the tape is placed in a magnetic tape cassette. Further, there arises a problem in that the tape edges are easily damaged, thereby inducing various types of problems and causing a deterioration of the electromagnetic conversion characteristics of the tape.
Therefore, in the prior art magnetic tape manufacturing process, all tapes must be visually checked with respect to the winding appearance after the aforementioned loading process. This adds significantly to the total cost and time required in the manufacturing process.
In order to reduce this checking burden, and for the purpose of improving the winding appearance, a method called "cap decorative winding", which is an open-type winding method and which is illustrated in FIG. 7, has been employed for loading a magnetic tape.
FIG. 7 is a schematic perspective view showing a take-up site tape winding body 2.
FIG. 7 shows the winding of a magnetic tape on a flangeless-type tape winding body while the magnetic tape T is pushed on one side by the weight of a cap 15 placed on the tape winding body mounted on a turntable 14 provided with a take-up shaft 4. According to this method, opposite edges of the tape T can be adjusted so that the tape T will have a good winding appearance after being wound on the tape winding body.
However, such an open winding type take-up method involves some risk of tape damage because it requires a process of placing the magnetic tape winding body in the cassette case. Further, the method results in certain assembling difficulties.
Another tape winding method, called "in-cassette winding", "C-0 winding" or "V-0 winding", has been proposed in which the magnetic tape is loaded only in the last step of the cassette assembly process. This method includes steps of assembling all parts in advance, except for the magnetic tape, into a cassette 8 as shown in FIG. 8 to form a unit into which a feed site tape winding body and a take-up site tape winding body connected by a leader tape 10 are inserted in the cassette. The leader tape is cut by use of a take-up apparatus called an "in-cassette winder". One end of a first leader tape is connected to one tape winding body of the cassette, while the other end of the leader tape is temporarily held by a holding member 16. The tape winding body 2, connected to the raw magnetic tape T through another leader tape, is rotated to take up the magnetic tape T. The magnetic tape T is cut off at a predetermined length. Lastly, a terminal end of the wound magnetic tape T is bonded to the other end of the first leader tape 10 to produce the finished article.
The above-described in-cassette winding type take-up method has an excellent manufacturing efficiency, but has disadvantages as follows. First, it is impossible to adjust the edges of the magnetic tape by contact as described above for cap decorative winding. Accordingly, the winding appearance will vary with the physical properties of the tape and the quality of various cassette parts, and hence the winding appearance cannot be controlled and sometimes is poor. Particularly, in the case where the tape winding body is of the flangeless type, it is very difficult to control the winding appearance.